Compound archery bows are well known in the field of archery. An early example of a compound archery bow is shown in U.S. Pat. No. 3,486,495 to Allen. A handle, or riser, supports upper and lower oppositely directed limbs. A pair of pulleys, or cams, are rotatably supported at the tips of the opposing limbs, and a bowstring extends between the two cams for driving an arrow. One or more cables also extend between the two cams to control the force required to pull the bowstring back as it is drawn from a rest position to a fully-drawn position.
The earliest compound bows typically used so-called solid limbs. For example, in the aforementioned U.S. Pat. No. 3,486,495 to Allen, each of the upper and lower limbs of the bow is a solid piece of material (wood, fiberglass, etc.) that is bifurcated at its distal tip end for allowing a pulley or cam to be positioned between the bifurcated ends of the distal tip end and pivotally mounted upon an axle supported by such bifurcated ends. More recently, compound bows have been provided with so-called split limb configurations wherein the former solid, relatively-wide upper limb is replaced by a pair of narrower, spaced “split” limb members. Examples of such split-limb compound bows are shown and described in U.S. Pat. No. 4,644,929 to Peck, and U.S. Pat. No. 5,720,267 to Walk.
The use of split limbs provides several advantages, including less weight and often faster arrow speed. On the other hand, the use of split limbs can complicate the secure coupling of the butt ends of the split limbs to the bow riser. As noted in the aforementioned U.S. Pat. No. 5,720,267 to Walk, the butt ends (innermost ends) of the split limbs are typically mounted to the bow riser by limb mounting pockets. As further noted by Walk, it is important to properly constrain the butt ends of the split limbs within the limb mounting pocket; in this regard, Walk describes a limb mounting pocket having a bottom member and a top member that is secured to the bottom member by a threaded bolt, in one embodiment, or as integral structure, in another embodiment, for enclosing the butt ends of the split limbs. Both the bottom member and top member have central dividers to form two channels in which the butt ends of the split limbs are held. However, Walk does not apply any lateral force against the sides of the split limbs within the limb mounting pockets.
The assignee of the present invention has found that manufacturing tolerances of the limb and limb mounting pockets tend to allow small spaces, or gaps, that allow the butt ends of the split limbs to move and shift laterally within the limb mounting pocket. Such lateral shifting can create limb alignment and bow tuning problems as the limbs, and the cams mounted at the ends of such limbs, move laterally over time. While those skilled in the art have attempted to provide limb mounting pockets that reliably lock the butt ends of the split limbs within the pocket in a manner that prohibits lateral movement of the limbs, such attempts have not provided a simple, inexpensive, and easily-manufactured limb lock for a limb mounting pocket.
Accordingly, it is an object of the present invention to provide a limb mounting pocket for a compound archery bow that reliably and securely maintains the butt ends of split limbs within the pocket in a manner that prevents lateral shifting of the limbs within the pocket.
Another object of the present invention is to provide such a limb mounting pocket that reduces the need to maintain strict manufacturing tolerances on the dimensions of the limb mounting pocket, and the split limbs, in order to prevent lateral shifting of the limbs within the limb mounting pocket.
Still another object of the present invention is to provide such a limb mounting pocket that can easily be accessed and operated after bow assembly to remove any lateral gaps or spaces between the sides of the bow limbs and the walls of the limb mounting pocket.
Yet another object of the present invention is to provide such a limb mounting pocket that simultaneously forces both of the split limbs against the outward walls of the limb mounting pocket with a single, rapid adjustment.
A further object of the present invention is to provide such a limb mounting pocket that is easy and inexpensive to manufacture.
These and other objects of the invention will become more apparent to those skilled in the art as the description of the present invention proceeds.